<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* 清除默认样式 */
    * {
      margin: 0;
      padding: 0;
    }
    ul,ol {
      list-style: none;
    }
    .lunbo {
      position: relative;
      width: 880px;
      height: 550px;
      border: 1px solid #333;
      margin: 20px auto;
    }
    .lunbo .pic li {
      position: absolute;
      left: 0;
      top: 0;
      width: 880px;
      height: 550px;
      display: none;
    }
    .lunbo .pic .current {
      display: block;
    }
    /* 按钮 */
    .lunbo .btn a {
      position: absolute;
      top: 50%;
      width: 40px;
      height: 40px;
      margin-top: -20px;
      background-color: rgba(255,255,255,0.3);
      font: 20px/40px "宋体";
      text-align: center;
      color: #fff;
      text-decoration: none;
      font-weight: bold;
    }
    .lunbo .btn .leftbtn {
      left: 20px;
    }
    .lunbo .btn .rightbtn {
      right: 20px;
    }
    .lunbo .btn a:hover {
      background-color: rgba(255,255,255,0.6);
    }
    /* 下标 */
    .lunbo .sub {
      position: absolute;
      left: 100px;
      bottom: 50px;
      width: 240px;
    }
    .lunbo .sub li {
      float: left;
      width: 20px;
      height: 20px;
      margin-right: 20px;
      background-color: rgba(255,255,255,0.4);
      font: 12px/20px "微软雅黑";
      text-align: center;
      color: #666;
      cursor: pointer;
    }
    .lunbo .sub .current {
      background-color: #fff;
    }
  </style>
</head>
<body>
  <!-- 轮播图大结构 -->
  <div class="lunbo" id = "lunbo">
    <!-- 图片部分 -->
    <ul class="pic" id= "pic">
      <li class="current"><img src="c1.jpg"></li>
      <li><img src="c2.jpg"></li>
      <li><img src="c3.jpg"></li>
      <li><img src="c4.jpg"></li>
      <li><img src="c5.jpg"></li>
      <li><img src="c6.jpg"></li>
    </ul>
    <!-- 按钮 -->
    <div class="btn">
      <a href="javascript:;" class="leftbtn">&lt;</a>
      <a href="javascript:;" class="rightbtn">&gt;</a>
    </div>
    <!-- 小圆点 -->
    <ol class="sub" id = "sub">
      <li class="current">1</li>
      <li>2</li>
      <li>3</li>
      <li>4</li>
      <li>5</li>
      <li>6</li>
    </ol>
  </div>
</body>
<script>
  var frame = document.getElementById('lunbo');
  var box = document.getElementById('pic');
  var lis = box.children;
  var ols = document.getElementById('sub').children;
  var timer = setInterval(move,3000);
  var idx = 0;
  function move(){
    if (idx > lis.length - 1)
        idx = 0;
    
    for (var i = 0; i < lis.length; i++)
    {
      lis[i].className = "";
      ols[i].className = "";
    }
    lis[idx].className = "current";
    ols[idx].className = "current";
    idx += 1;
  }
  frame.onmouseover = function () {
            clearInterval(timer);
        };
  frame.onmouseout = function () {
            timer = setInterval(move,3000);
        };


</script>
</html>